Spare 400 rd Wind Up High Capacity Magazine for the Cybergun made SIG 556 AEG rifle. This magazine is slightly longer than the original 300 rd magazines which came with the rifle however it can still be interlocked with them.

Authentic SIG markings.

400 rd capacity, larger than original magazine.

Interlocks with original magazines.

Also compatible with some M4/M16 series AEG such as the Full Metal ECHO 1 MOD4 and ECHO 1 M4 Platinum rifles. However, due to the design of the magazines interlocking system they will NOT fit into most ABS bodied models or the KWA series rifles.